Focal segmental glomerulosclerosis variants in children with nephrotic syndrome

Introduction The aim of this study was to determine pathological variants of childhood focal segmental glomerulosclerosis and assess efficacy of prednisolone + methylprednisolone + cyclosporin A treatment. Materials and methods This retrospective cohort study included 134 native Kazakh children (3 months–17 years) with nephrotic syndrome hospitalised in the Nephrology Department of the Republic Children’s Clinical Hospital from 2004 to 2011. Kidney biopsy and pathological investigations were performed in 38 nephrotic syndrome patients with proven steroid resistance. Results Focal segmental glomerulosclerosis was confirmed in 38 (28.4%) patients (treatment group). The main focal segmental glomerulosclerosis variants were glomerular tip lesions and not otherwise specified types. Historical (did not undergo kidney biopsy) controls were treated with cyclosporin A or alkylating agents. Prednisolone + methylprednisolone + cyclosporin A immunosuppressive therapy was highly effective, allowing complete remission in 88.9% patients with minimum side effects. Patients with the not otherwise specified variant (NPHS2 and WT1 mutations) did not achieve remission. Combination cyclosporin A treatment was significantly more effective than alkylating agent treatment in steroid-resistant nephrotic syndrome patients without genetic mutations. Conclusion Tip lesions are predominant in childhood steroid-resistant nephrotic syndrome. Prednisolone + methylprednisolone + cyclosporin A therapy is safe and effective for childhood focal segmental glomerulosclerosis. Establishing a podocyte mutation profile is important to predict treatment outcome.